1. Field of the Invention
The present invention relates to a lighting apparatus using microwave energy, and more particularly, to a lighting apparatus using microwave energy which is capable of radiating heat generated in a microwave generator outside of a casing.
2. Description of the Background Art
A lighting apparatus using microwaves emits visible rays or ultraviolet rays by applying microwaves to an electrodeless lamp. Such a device has a longer lifespan and provides better lighting efficiency than that of an incandescent lamp or a fluorescent lamp.
FIG. 1 is a longitudinal, sectional view illustrating a lighting apparatus using microwaves in accordance with the background art.
The lighting apparatus using microwaves is constructed with a front casting 1, a rear casing 2, a waveguide 3 for transmitting microwaves generated in a magnetron 10, and a high voltage generator 4 for boosting the AC power and supplying it to the magnetron 10.
A reflecting mirror 6 for reflecting light generated in a bulb 5 towards the front is installed at the exterior of the front casing 1.
The magnetron 10 generating microwaves is installed at the side wall of the waveguide 3. The bulb 5 generating light with enclosed materials in a plasma state by microwave is installed at the upper portion of the waveguide 3. A resonator 8 for passing the light emitted in the bulb 5 while cutting off the microwaves covers the front side of the bulb 5 and is assembled so as to project from the front casing 1.
A bulb motor 7 is connected to the bulb 5 with a shaft 5a and rotates the bulb 5 in order to cool it down.
A fan housing 9a having a suction hole 2a and a discharge hole 2b is placed in the rear casing 2 in order to cool down the magnetron 10 and the high voltage generator 4, etc.
A cooling fan 9b is installed inside the fan housing 9a, and a fan motor 9c which operates the cooling fan 9b is installed inside the rear casing 2.
An outlet 1a is formed at the front casing 1 in order to discharge the air drawn in by the operation of the cooling fan 9b after cooling down the elements inside the casing.
FIG. 2 is a sectional view taken along the line of Axe2x80x94A of FIG. 1. It illustrates the structure of the magnetron of the lighting apparatus using microwave in accordance with the background art.
The magnetron 10 includes a housing 19 containing the elements for generating microwaves and a filter box 20 connected to the high voltage generator 4, shown in FIG. 1 for applying the boosted voltage and having a condenser 21 and a choke coil 23 for performing a filter function. An output pipe 25 extends inside of the waveguide 3, as shown at FIG. 1 for outputting microwave is placed at the front of the housing 19.
Inside the housing 19, there is a cathode unit 15 having a filament shape which emits a large amount of heat electrons by being heated with power applied through the filter box 20; an anode unit 11 generating microwaves by moving the electrons from the cathode unit 15 between a vane 13 and a strap 14 at a requested frequency bandwidth according to certain rules when a fixed amount of anode voltage and anode currents are applied to an anode body 12 having a cylinder shape; an antenna 16 for transmitting the microwave energy generated in the operation space of the anode unit 11 and the cathode unit 15 inside the waveguide 1 as shown at FIG. 1; and permanent magnets 17a, 17b respectively installed at the upper portion and the lower portion of the anode body 12 of the anode unit 11 and forming a lock down circuit.
Inside the housing 19 a cooling pin 18 is installed at the circumference of the anode body 12 of the anode unit 11. It has a wave structure and forms an air-cooling structure inside the housing 19 by being assembled in a plurality of layers uniformly arranged at the circumference of the anode body 12.
The operation of the lighting apparatus using microwave energy in accordance with the background art will now be described.
As depicted in FIG. 1, when an operational signal is inputted to the high voltage generator 4, the high voltage generator 4 boosts the AC power and supplies it to the magnetron 10.
The magnetron 10 generates microwave energy having a very high frequency by being oscillated by the high voltage supplied from the high voltage generator 4. The generated microwave energy is emitted inside the resonator 8 through the waveguide 3, excites the materials enclosed in the bulb 5 and generates light having an inherent emitting spectrum.
The light generated in the bulb 5 collectively reflects toward the front through the reflecting mirror 6 and lightens the adjacent space.
In the process of generating the lumination by microwave energy, heat having a high temperature is generated at the inner side of the anode unit 11 of the magnetron 10, and this heat is transmitted to the housing 19 through the cooling pins 18. Also, part of the heat is radiated inside the casings 1, 2.
The cooling fan 9b is rotated by the motor 9c and air which is drawn in from the outside through the suction hole 2a of the rear casing 2 cools the magnetron 10 and the casings 1, 2. The air which cools the magnetron 10 is discharged to outside through the outlet 1a of the front casing 1.
However, in the lighting apparatus using microwave energy in accordance with the background art, because the fan motor 9c and the cooling fan 9b installed in order to cool down the magnetron 10 are noisy, it is undesirable to use such a device in spaces which require calm and quiet lighting such, as an office and in the home, etc.
In addition, when the lighting apparatus using microwave energy in accordance with the background art is installed at outside, impurities such as bugs and dust can be drawn into the casings 1, 2 through the suction hole 2a and the outlet 1a, covering the internal parts of the apparatus with dust and the dead bodies of bugs. In such cases, the impurities may affect the electric circuits or operational elements of the system causing mechanical problems.
In addition, in lighting apparatus using microwave energy, in accordance with the background art, because the cooling pins 18 are placed inside the magnetron 10 and the fan housing 9a, the cooling fan 9b and the fan motor 9c are installed at the rear of the casings 1, 2, making the structure of the lighting system intricate, and increasing the volume or size of the lighting system such that it occupies much space.
In order to solve the above-mentioned problems, it is an object of the present invention to provide a lighting system using microwave energy which is capable of being used in circumstances requiring a low noise, by reducing the occurrence of noise caused by the fan and fan motor by irradiating the heat generated in the magnetrons by providing a heat pipe having good heat conductivity between the magnetron and a casing, etc. without using the fan and the fan motor.
In addition, it is another object of the present invention to provide a lighting apparatus using microwave energy which is capable of improving the reliability of a lighting system by sealing a casing hermetically so as to prevent penetration of impurities such as bugs and dust by constructing a lighting apparatus so as to radiate heat outside of the casing by a heat transfer method.
In order to achieve the above-mentioned objects, a lighting system using microwave energy in accordance with the present invention includes a microwave generator installed inside a casing and generating microwave energy, a waveguide for transmitting the microwave energy oscillated by the microwave generator, a resonator for covering the outlet of the waveguide, cutting off any leakage of the microwaves and passing light, a bulb placed inside the resonator for generating light by the microwave energy transmitted through the waveguide, a conduction block closely adhered to the microwave generator, to which heat generated in the microwave generating process is transmitted, a heat transfer means connected between the conduction block and the casing for transmitting heat from the conduction block to the casing, and a radiating means installed at the end of the heat transfer means for radiating heat transmitted from the conduction block outside of the casing.
In addition, in order to achieve the above-mentioned objects, a lighting apparatus using microwave energy in accordance with the present invention includes a microwave generator installed inside a casing and generating microwave energy, a waveguide for transmitting the microwave energy oscillated by the microwave generator, a resonator for covering the outlet of the waveguide, cutting off leakage of the microwave energy and passing light, a bulb placed inside the resonator and generating light by the microwave energy transmitted through the waveguide, a conduction block adhered closely to the microwave generator, to which the heat generated in the microwave generating process is transmitted, a heat pipe installed between the conduction block and the exterior of the casing in order to transmit the heat by using latent heat of a working fluid, and a radiating means installed at the end of the heat pipe for radiating the heat transmitted through the heat pipe to the outside of the casing.
In addition, in order to achieve the above-mentioned objects, a lighting system using microwave energy in accordance with the present invention includes a microwave generator installed inside a casing for generating microwave energy, a waveguide for transmitting the microwave energy oscillated by the microwave generator, a resonator for covering the outlet of the waveguide and eliminating the leakage of microwave energy and passing light, a bulb placed inside the resonator for generating light by the microwave energy transmitted through the waveguide, a conduction block adhered closely to the microwave generator, to which the heat generated in the microwave generating process is transmitted, a heat pipe installed between the conduction block and the interior of the casing for transferring the heat by using the latent heat of a working fluid, and a metal member having high heat conductivity for radiating heat transmitted through the heat pipe.
In addition, in order to achieve the above-mentioned objects, a lighting system using microwave energy in accordance with the present invention includes a microwave generator installed inside a casing for generating microwave energy, a waveguide for transmitting the microwave energy oscillated by the microwave generator, a resonator for covering the outlet of the waveguide, and eliminating the leakage of the microwave energy and passing light, a bulb placed inside the resonator for generating light by the microwave transmitted through the waveguide, a conduction block adhered closely to the microwave generator, to which the heat generated in the microwave generating process is transmitted, a heat conduction rod installed at the conduction block and the inner surface of the casing in order to transmit heat from the conduction block to the inner surface of the casing, and a metal member having a high heat conductivity for radiating heat transmitted through the heat pipe.
In addition, in order to achieve the above-mentioned objects, a lighting system using microwave energy in accordance with the present invention includes a microwave generator installed inside a casing for generating microwave energy, a waveguide for transmitting the microwave energy oscillated by the microwave generator, a resonator for covering the outlet of the waveguide, and eliminating the leakage of the microwave energy and passing light, a bulb placed inside the resonator for generating light by the microwave energy transmitted through the waveguide, a conduction block adhered closely to the microwave generator for receiving the heat generated in the microwave generating process, said conduction block being connected to the inner surface of the casing in order to transmit the heat to the inner surface of the casing, and a casing constructed with a metal member, at least one part of which having a high conductivity in order to radiate heat transmitted through the conduction block to the outside.
The lighting system using microwave energy in accordance with the present invention can prevent the occurrence of noise while in use by not using a cooling fan and a fan motor, etc. and accordingly, can be used in quiet environments, such as an office, home, etc.
In addition, the lighting apparatus using microwave energy in accordance with the present invention reduces mechanical troubles caused by uncleanness and impurities, by hermetically sealing the casing which reliability improves the lighting system.
In addition, the lighting system using microwave energy in accordance with the present invention provides a simpler and smaller structure and accordingly can be installed in a small space.
Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.